Process of manufacturing cyanides



Patented Sept. 3, 1929.

UNITED STATES PATENT OFFICE.

HERMANN WIEDEBHOLD, OI FURSTENWALDE-ON-THE-SPREE, GERMANYpA ssIGNon TO THEzFIRM N. V. NEDERLANDSCHE EIJNBOUW EN HANDED MAATSGHAPPIJ,

OF AMSTERDAM, NETHERLANDS.

PROCESS OF MANUFACTURING CYANIDES.

Ho Drawing. Application flled liovember 18, 1926, Serialv No. 149,284, and in Germany December 10, 1925.

My invention relates to improvements in the process of manufacturing cyanides.

In the manufacture of alkali metal or barium cyanides in which nitrogen is caused to act on mixtures of substances containing carbon and oxides or carbonates hf the alkali metals and the barium at elevated temperature the binding of the nitrogen should be effected as rapidly and completely as possible. A rapid binding is obtained if the coal and the metal compound are intimately mixed, the coal has a high degree of activity, and the nitrogen has a ready access to the mixture. The object of. the improvements is to provide a process by means of which products answering this condition are obtained and, accordingly, alkali metal and barium cyanides are rapidly and economicallyproduced. With this object in view my invention consists in manufacturing the said products from substances capable of producing highly active coal and having the property of producing a granular product when heated in mixture with alkali metal and barium compounds. A suitable matter of this character is the humic acid.

Humic acid or alkali metal humates obtained from matter containing humic'acid are mixed with a sufiicient excess of alkali metal or barium oxides or carbonates, and the mixture is heated while continuously removing the gaseous products. Thus a granular highly active coke is produced which is rich in alkali. metal or barium.

Preferably in a separate oven, or in a second chamber of the same oven, the said coke is subjected to the second step of the process, in which it is heated in the nitrogen current at a temperature of about 1000 C.

or more. By reason of the porosity of the granular coke the nitrogen is rapidly absorbed, and the alkali metal or barium oxide is almost completely used up for producing cyanide.

To the initial substance suitablecatalysts such for example as iron compounds may be admixed, and I have found that as .compared to processes heretofore in use. small amounts of the catalyst result in a considerable acceleration of the reaction and in an improved yield.

Free humic acid is found natural mainly in' the form of the so called coal humus which, by reason of its brown colour, is also used as an earth dyestuff known in the trade as brown of Cassel. In some cases the coal humus contains much earth. Therefore I prefer to treat the same with alkali metal carbonate, to separate the solution of alkali metal humate from the earth, andto obtain the alkali metal humate pure while removing the water in a suitable way.

In some cases I break up matter such as peat or certain kinds of brown coal containing much humic matter by alkali metal compounds or by pressure hydrolysis with steam,

in which case free humic acid or alkali metal humates are produced from the humic substances whlch in my opinion are of the nature of anhydrides, the said humic acid or,

alkali metal humate being separated and subjected to the above rocess.

I have found that w en heating the ure alkali metal humates," and more particularly those obtained from coal humus, a material is obtained the binding power of which is so high that a granular porous coke can be obtained even if to the humates other produots containing carbon are added which when heated by themselves do not yield suitable coke. I have discovered that u to about 60% of the said matter can be a ded.

The alkali metal compound can be added to the initial materials in the form of concentrated waste lyes of the industry which are IlCl'l in alkali metal compounds, and

even such lyes may be used which have or is developed. After 10 or 15 minutes the,

material is removed from the drum in the form of a dark brown or black glutinous and doughy material. The said materialis heated within a rotary oven up to 550 C.

After thus heating the matter about 30 or- 40 minutes, a compact coke is obtained the particles of which have the size of peas or drum of a length of 3 meters with 1 he toliter of walnuts. which coke is subjected to the amground and boiled with 150 kilograms of sodium carbonate and water while stirring.

Thereafter the suspension is allowed to settle, and the solution is decanted from the sediment formed, whereu on the solution containing the alkali meta humate obtained by the rocess is thickened as far as necessary be ore heating the same. Thereafter the thickened matter containing about 250 kilograms of alkali metal humate is mixed with 20 kilograms of Fe O heated and azotized.

I claim: 1. The herein described process of manufacturing cyanides, which comprises heating matter containing free humic acid in the presence of a. compound of an \alkali metal and heating the coke thus produced at a temperature of at least about 1000 C. while causin nitr en to act on the same.

e herein described process of manufacturingcy'anides, which comprises heating alkali metal humate, and heating the coke thus produced at a temperature of at least about 1000 C. while causing nitrogen to act on the same.

3. The herein described process of manufacturing cyanides, which comprises heating matter containing humic acid in the presence of an alkali metal compound toproduce a granular coherent coke, and heating the said coke at a temperature of at least about 1000 C. while causing nitrogen to act on the same. Y

4. The herein described process of manufacturing cyanides, which comprises heatinga mixture of matter containing humic acid in the presence of an alkali metal compound and a suitable carbon carrier, and heatin the coke thus produced at a temperature 0 at least about 1000 C. while causing nitrogen to act on the same.

,5. The herein described process of manufacturing cyanides, which comprises treating matter containing free humic acid in the presenceof water with a suitable alkali metal compound, separating the solution from the solid residue, thickening the solu tion, heating the thickened matter to produce a granular coke therefrom, andheating the coke thus produced at a temperature of at least about 1000 C. in the presence of nitrogen.

6. The herein described process of manu- O are finely matter containing humic substances with a basic alkali metal compound, separating therefrom the solid matter, thickening the solution by evaporation, heating the product in the presence of an alkali metal comound to form a coke therefrom, and heatmg the coke thus produced at a temperature of'a-t least about 1000" G. in the presence of nitrogen.

7. he herein described process of manufacturing cyanides, which comprises heating matter containing humic acid in the presence of alkali metal salts, and a suitable catalyst, and heating the mixture thus produced at a temperature of about 1000 C.

in the resence of nitrogen.

8. T e herein described process of manufacturing cyanides, which comprises heating I matter containinghumic acid in the presence of an alkali metal compound,and a metal of the iron group as a catalyst, and

heating the mixture thus produced at a temperature of at least about 1000 the presence of nitrogen. 1

9. The herein described process of manufacturing cyanides, which comprises treating matter containing humic substances with water by heating under pressure, dis-.

solving the formed free humic acid by adding a basic alkali compound, separating from the solution the solid matter, thickening the solution by evaporation, heating the product in the presence of an alkali metal compound to produce coke therefrom, and heating the coke thus produced at a tempefi ature of at least about 1000 C. in the presence of nitrogen.

10. The process of forming cyanogen compounds by causing nitrogen to react with a charge comprising a basic compound of a metal selected from the alkali and alkaline earth metals and carbon produced by the carbonization of a humate.

11. The process of forming cyanogen compounds by causing nitrogen to react with a charge comprising an oxidic compound of metal selected from the alkali and alkaline earth metals and carbon produced by the carbonization of a humate of such a metal.

12. The process of forming cyanogen compounds by causing nitrogen to react with a charge comprising a basic compound of an alkali metal and carbon produced by the carbonization of a humate.

In testimony whereof I hereunto afix my 

